| First Author | Ishikawa K | Year | 2022 |
| Journal | Gastroenterology | Volume | 163 |
| Issue | 5 | Pages | 1391-1406.e24 |
| PubMed ID | 35963362 | Mgi Jnum | J:361114 |
| Mgi Id | MGI:7379370 | Doi | 10.1053/j.gastro.2022.07.081 |
| Citation | Ishikawa K, et al. (2022) Identification of Quiescent LGR5(+) Stem Cells in the Human Colon. Gastroenterology 163(5):1391-1406.e24 |
| abstractText | BACKGROUND & AIMS: In the mouse intestinal epithelium, Lgr5(+) stem cells are vulnerable to injury, owing to their predominantly cycling nature, and their progenies de-differentiate to replenish the stem cell pool. However, how human colonic stem cells behave in homeostasis and during regeneration remains unknown. METHODS: Transcriptional heterogeneity among colonic epithelial cells was analyzed by means of single-cell RNA sequencing analysis of human and mouse colonic epithelial cells. To trace the fate of human colonic stem or differentiated cells, we generated LGR5-tdTomato, LGR5-iCasase9-tdTomato, LGR5-split-Cre, and KRT20-ERCreER knock-in human colon organoids via genome engineering. p27(+) dormant cells were further visualized with the p27-mVenus reporter. To analyze the dynamics of human colonic stem cells in vivo, we orthotopically xenotransplanted fluorescence-labeled human colon organoids into immune-deficient mice. The cell cycle dynamics in xenograft cells were evaluated using 5-ethynyl-2'-deoxyuridine pulse-chase analysis. The clonogenic capacity of slow-cycling human stem cells or differentiated cells was analyzed in the context of homeostasis, LGR5 ablation, and 5-fluorouracil-induced mucosal injury. RESULTS: Single-cell RNA sequencing analysis illuminated the presence of nondividing LGR5(+) stem cells in the human colon. Visualization and lineage tracing of slow-cycling LGR5(+)p27(+) cells and orthotopic xenotransplantation validated their homeostatic lineage-forming capability in vivo, which was augmented by 5-FU-induced mucosal damage. Transforming growth factor-beta signaling regulated the quiescent state of LGR5(+) cells. Despite the plasticity of differentiated KRT20(+) cells, they did not display clonal growth after 5-FU-induced injury, suggesting that occupation of the niche environment by LGR5(+)p27(+) cells prevented neighboring differentiated cells from de-differentiating. CONCLUSIONS: Our results highlight the quiescent nature of human LGR5(+) colonic stem cells and their contribution to post-injury regeneration. |
